Process of treating fresh unused petroleum oils to produce decolorized lubricating oil stocks



June 23, 1936. A, R MQQRMA'N ET AL 2,045,160 PROCESS OF TREATING FRESHUNUSED PETROLEUM OILS TO PRODUCE DECOLORIZED LUBRICATING OIL STOCKS 7Filed Novr 26, 1929 smnnas gwvenfm Patented June 23, 1936 UNITED, STATESPATENT OFFICE PROCESS OF TREATING FRESH UNUSED PETROLEUM OILS TO PRODUCEDECOL- ORIZED LUBRICATING OIL STOCKS Arthur R. Moorman, Woodriver, Ill.,and Irving C. Carpenter, New Rochelle, N. Y., assignors to ContactFiltration Company, San Francisco, Calif., a corporation of DelawareApplication November 26, 1929, Serial No. 409,863

4 Claims.

Hitherto lubricating oils manufactured from residuals have generallybeen decolorizedby per- 19 colating the oils through a decolorizing clayat low temperatures. When the hot contact method of treating oils todecolorize the same was applied to lubricating oil stocks derived as aresiduum from reducing crude petroleum oil, it was found l3 thatexcessive quantities of clay were required to decolorize the oil.

Basically, the hot contact process of decolorizing oils diifers from thepercolating operation in the following respects. In a percolationprocess the clay is maintained in a bed of comparatively coarseparticles while the oil at from normal temperature to about 250 F.percolates slowly through the bed. In the hot contact process comminutedclay is used and agitated with oil at elevated temperatures over 250 F.and generally from 350 to 550 F.

We have discovered that the amount of clay required to decolorizecertain residuums may bereduced from 25% to 50% by the followingprocedure.

The neutral oil is first passed through a heating chamber to vaporize aportion of the oil; the heated oil is then passed to a chamber in whichthe vaporized portion of the oil is separated from the unvaporizedportion of the oil. which unvaporized portion is thus reducedto asuitable residuum for the manufacture of lubrieating oils, the residuumso derived while still hot is agitated with the comminuted decolorizingagent, cooled, and the agent separated from the oil. This procedureproduces at a low cost a decolorized oil by the hot contact method wherepreviously the cost of treatment has been excessively high.

The process has been found particularly eifective on Pennsylvanianresiduum consisting of from 12% to 35% of the original crude whoseasphaitic content is sufficiently low as to permit of completedecolorization with the use of clay only. Also the process is foundeffective on treated, clay neutralized topped crude. The latter coversthe use of mid-continent stocks in which the crude is topped taking oifthe gasoline and kerosene and the residuum from this operation is acidtreated and the oil neutralized by treatment with clay, filtered fromthe clay, the oil thus prepared requiring further reduction anddecolorization to produce a residuum of the generally acceptedspecifications. In any event, the oil processed is eitherinherently'neutral or is neutralized prior to its introduction into theprocess.

The method of treating the oil to decolorize the same and producelubricating oils of accept-, able specifications in accordance with thepresent invention will best be understood from a description of apreferred form or example of. a process embodying the invention. Forthis purpose there is hereafter described a preferred form or example ofa process embodying the invention. It should be understood, however,that the particular details of treatment will vary somewhat widelydepending on the particular oil processed and the kind of lubricatingoil and color to which the lubricating oil is to be decolorized.

The process is described with reference to the accompanying drawing, inwhich:

The figure represents a diagrammatic view on flow sheet of an apparatussuitable for conducting the process.

Referring to the drawing, the raw material is picked up by pump 2 whichdischarges through a'heater 3 where sufficient heat is imparted to theoil to permit of the vaporization and fractionation of sufficient of.the charge in fractionating tower 4, as to leave a residuum of therequired physical specifications for lubricating oil. The fractionatingtower 4 may be of any design suitablefor this operation and well knownin the art for fractionation of vapors in oil discharged from a heatersuch as the heater 3. The lighter fractions leave the fractionatingtower 4 to a suitable condensing device (not shown) through line 5,leaving as a residue in tower 4, an oil or residuum satisfactory withregard to physical tests but requiring decolorization to produce afinished product.

The pump 6 takes suction on the bottom of tower 4 and discharges the hotresiduum into a mixing chamber or tank 8 into which cla from a source(not shown) is introduced at I. In order to supply the necessaryagitation or turbulenceto insure intimate contact and at the same time,supply the heat lost by the oil heating the clay and vaporizing anywater in the clay. pump 9 takes suction on mixing tank 8 and dischargesthrough heater l back into mixing tank 8, such vapors as may be producedbeing drawn oil at ii.

The outlet to heater I0 is provided with a valve II by means of whichthe clay and oil mixture is removed from the system by opening valve I Iand starting pump l2. The amount removed by this means is proportionalto the quantity entering the mixing tank 8 through pump 6. Pump l2discharges through a cooler l3 and filter ll, where the clay and oil areseparated, the clay being discarded and the oil passing through a coolerl5 into storage I.

Various comminuted decolorizing agents well known in the art may be usedand these may be applied either dry or in the wet state. Acid treatedclay of the montmorillonite class are especially suited for the process.

To illustrate the specific temperatures existing throughout the systemwhen operating on a typical example of a 42 Baum Pennsylvania crude, thefollowing temperatures are given. Crude enters heater 3 at F'. Crudeleaves heater 3 at 750 F. Vapors leave tower 8 at 550 F. Residuum leavespump 6 at 500 F. Clay and oil mixture is maintained in tank 8 at 475 F.Clay enters tank 8 at 70 F. Oil-clay mixture leaves pump 8 at 475 F.Oil-clay mixture leaves heater ID at 500 F; Oil-clay mixture leavescooler it! at 200 F. 011 leaves cooler l5 at F.

The amount of clay ,used per gallon of oil to produce an oil of 6N. P.A. color varies from 0.5 pound to 1.25 pounds; whereas, the same oilspreviously had required from 0.65 pound to 1.7

pounds of clay per gallon of oil. These figures represent a saving inthe 30% to 40%.

In certain cases, in order to maintain complete continuous operation ofthe process and to adjust the reducing operations relative to thedecolorizing operations it may be desirable to insert a surge tankbetween the tower 4 and mixing chamber 8 to compensate for slightfluctuations in capacities between these units. This may be done withoutseriously effecting the operation as a whole. The temperature of the oilentering the mixing tank 8 should be as near that of the oil leavingtower 4 as practical operations will permit. Any reduction intemperature results in an increase in the amount of clay required intank 8. Thus if the stock is cooled to 200 15. before entering thechamber 8, there is a marked increase in the quantity of 'clay requiredto produce any given color as compared to the same oil where the coolinghas not been allowed to go below 400 F. Even where the oil enters themixing chamber 8 at temperatures as low at 200 F., a much moreeconomical operation is effected than the general practice of the priorart where the oil is .ntroduced at atmospheric temperature into themixing tank.

Preferably; agitation in mixing tank 8 takes place in absence of air andthe introduction of wet clay facilitates the operation due to theevaporation of the water from the clay forming a blanket of steam whichprevents oxidation of .the oil.

The oil may be "stored at temperatures as high as 500 F. for severalhours after leaving the tower 4 and before entering mixing chamber 8 ifdesired without darkening in color, especially if the oil is blanketedwith steam at all times to prevent oxidation. Long standing of the oilat high temperatures, however, is to be avoided with oil rich inunsaturated straight, chain and present process of from cyclic compoundswhich tend to polymerize under heat.

Pennsylvania oils almost without exception may be more economicallydecolorized without than with the use of acid. Other oils such asreduced mid-continent crude may be acid treated and then neutralized byhot clay treatment prior to its introduction into the distilling unit ofthis process.

- No particular explanation of the saving of clay eflected by thepresent process is set forth for the reason that cause of or reason forsuch saving is not entirely known.

While the particular process herein described is well adapted to carryout the objects of the present invention. various modifications may bemade without departing from the principles of the invention, and allsuch modifications and changes come within the scope of the appendedclaims.

We claim:

1. A process of treating fresh unused petroleum oils to producedecolorized lubricating 011 stocks, which comprises passing an oil amember of the group including neutral parafiine base crudes and acidtreated clay neutralized topped asphaltic base crudes through a heatingchamber to vaporize a portion of the oil and reduce the residuum tolubricating oil stock, and promptly thereafter .which comprises passingan oil a member of the group including neutral parafilne base crudes andacid treated clay neutralized topped asphaltic base crudes through aheating chamber to vapor-. ize a portion of the oil and reduce theresiduum to lubricating oil stock, and promptly thereafter while the oilis still not adding thereto a decolor- -izing clay, agitating the clayand oil while heating the mixture, and finally cooling and separatirgthe oil fromthe clay.

3. A process of treating fresh unused petroleum oils to producedecolorized lubricating oil stocks, which comprises passing an oil amember of the group including neutral parafiine base crudes and acidtreated clay neutralized topped asphaltic base crudes through a heatingchamber to vaporize a portion of the oil and reduce the residuum tolubricating oil stock, and promptly thereafter while the oil is stillhot adding thereto a wet decolorizing clay, agitating the clay and 011while heating the mixture, and finally cooling and separating the oilfrom the clay.

ARTHUR R. MOORMAN. IRVING -C. CARPEIITER.

